1. Field of the Invention
This invention relates to electrical inspection apparatuses that perform electrical inspection by bringing inspection probes into contact with printed circuit boards (or printed wiring boards).
This application claims priority on Japanese Patent Application No. 2003-14146, the content of which is incorporated herein by reference.
2. Description of the Related Art
Conventionally, printed circuit boards (simply referred to as printed boards) having electrode patterns are subjected to inspection upon detection of electrical conduction of wiring thereof In this case, an inspection apparatus is used to perform inspection by bringing an inspection probe thereof into contact with each of the contacts, which have the structure allowing detection of electrical conduction upon electrification via contact terminals and the like, are arranged on a printed board, an example of which is disclosed in Japanese Patent Application Publication No. Hei 11-340588. This inspection apparatus uses a printed board in which a circuit pattern is formed on an insulating film in which numerous contacts are arranged on the surface and are conducted with the circuit pattern, wherein a prescribed material such as copper having plastic deformation ability is used for the circuit pattern. In inspection, a printed board is fixed onto the upper surface of an inspection instrument, which is horizontally arranged; then, an inspection probe descends down to the printed board and is brought into contact with a prescribed contact of the printed board, thus performing inspection as to whether or not an electrical conduction is established.
However, the aforementioned inspection apparatus may sometimes fail to perform inspection in a stable manner with a sufficiently high accuracy. When inspection is performed on a flexible printed board, for example, the flexible printed board is kept wound up in a roll, so that it may not always maintain a planar condition. For this reason, when such a flexible printed board is subjected to inspection by the inspection apparatus, the printed board may be deflected in shape so that an inspection probe cannot be reliably brought into contact with a prescribed contact of the printed board. Even when the inspection apparatus is equipped with a fine inspection probe having a high positioning accuracy, the fine inspection probe may be easily damaged due to the deflection or deformation of the printed board beyond physical tolerance thereof.